High Definition Vehicular Mirror

ABSTRACT

A vehicle mirror assembly having a housing or base member, a mirror lens and a connecting gasket member. The mirror lens is provided in the shape of a portion of an end of an ellipsoid. The lens has a varying radius of curvature, The center portion of the lens has a smaller radius of curvature than the outer portions along the major axis of the lens creating an improved field of view of the reflected image.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. application Ser. No. 10/908,038 filed onApr. 26, 2005, which is a continuation-in-part of U.S. application Ser.No. 10/708,123 filed on Feb. 10, 2004.

TECHNICAL FIELD

The present invention relates generally to exterior automotive mirrorassemblies and, more particularly, to front-end mounted exteriorautomotive ellipsoid mirrors which provide improved images.

BACKGROUND OF THE INVENTION

Automotive mirror assemblies can play a vital role in vehicle operation.Placement of the vehicle operator within the vehicle structure oftenmakes direct line-of-sight to surrounding vehicle areas impractical. Yetsuch visual inspections of surrounding areas can provide the vehicleoperator with information necessary for proper vehicle operation. Asvehicle size increases, so often does the difficulty of accurate visualinspections. Vehicles, such as school buses and commercial vans, oftenutilize increased vehicle sizes while requiring visual inspection ofareas in front of and to the side of the vehicle. To this end, it iswell known that vehicle mirrors may be front-end mounted to the vehicleto provide the widest possible field of view around the vehicle.

Early attempts at widening the operator's field of view focused on theuse of convex mirrors. By increasing the size of the convex mirror, itwas discovered that the field of view could be increased. Unfortunately,increasing the size of the convex mirror is inefficient as the mirroritself begins to become an obstruction to forward viewing. Toaccommodate the need for increased field of view without negativelyimpacting mirror size, it is known that a domed mirror lens mayincorporate a varying radius of curvature along one of either the majoror minor axis. The varying radius of curvature achieves a compacted widefield of view or viewing area within minimal space such that the drivercan look forward of the vehicle with minimal blockage of vision, Thesemirrors with varying radius of curvature along one axis are commonlyreferred to as crossover mirrors.

Although the use of cross-over mirror designs has proven highlysuccessful in the increase of viewing area while minimizing mirror size,present designs still can incorporate drawbacks. One of the drawbacks ofthese common cross-over mirror designs results from the reflection ofthe vehicle itself within the mirror, In many designs, the vehiclereflection is positioned within the center of the mirror and fills asignificant amount of valuable viewing space. This results in areduction of useful mirror surface area since the user does not commonlyneed to monitor reflection of the vehicle itself. Furthermore, imagesreflected in the mirror along the front and side of the vehicle oftenappear in the perimeter regions of the mirror. The reflections in theperimeter regions are commonly reduced in proportion due to decreasingsurface radius of curvature in these regions of the mirror. This canresult in undesirably distorted images with reduced image proportionssuch as long thin images. The reduction in image proportion can resultin an increased strain on the driver to differentiate the objectsreflected in these regions.

It would, therefore, be highly desirable to have a mirror assembly thatreduces the size or amount of vehicle reflection in the mirrorreflective surface area and increases the size and amount of reflectionof the other areas. It would further be highly desirable to have amirror assembly that improves image proportional reflection along themirror perimeter to facilitate improved recognition.

SUMMARY OF THE INVENTION

A vehicle mirror assembly is provided comprising a base. The basecomprises a first base portion defined by a first base longitudinal lineand a first base periphery. The first base portion has a first baseradius of curvature, The base further includes a second base portiondefined by the first base longitudinal line and a second base periphery.The second base portion has a second base radius of curvature. A domelens conforms to the base. The dome lens has a varying dome lens radiusof curvature. The dome lens comprises a center surface portion having acenter surface radius of curvature. The center surface radius iscorresponding to a position on said dome lens aligned with a first baselongitudinal midpoint to said dome lens and is perpendicular to thefirst base longitudinal line. A peripheral surface portion has aperipheral surface radius of curvature corresponding to the first baseperiphery. The peripheral surface radius of curvature is greater thanthe center surface radius of curvature.

In a preferred embodiment, the mirror lens is formed as a portion of anend section of an ellipsoid. With the present invention, the reflectedimage of the vehicle can be reduced 25% or more, while objects adjacentthe outer perimeter of the reflected image can have the sizes of theirimages increased by 50% or more.

Other features of the present invention will become apparent when viewedin light of the detailed description of the preferred embodiment whentaken in conjunction with the attached drawings and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of an ellipsoid vehicle mirror assembly inaccordance with the present invention mounted on a vehicle.

FIG. 2 is rear perspective view of the ellipsoid vehicle mirror assemblyillustrated in FIG. 1.

FIG. 3 is an alternate embodiment of an ellipsoid vehicle mirror inaccordance with the present invention.

FIG. 4 is a cross-sectional view of the ellipsoid vehicle mirrorassembly shown in FIG. 1, the view illustrating the geometric propertiesof the ellipsoid vehicle mirror,

FIG. 4A is an enlarged view of a portion of the mirror depicted in FIG.4 illustrating a preferred embodiment of the present invention.

FIG. 5 is a front perspective view of the ellipsoid vehicle mirrorillustrated in FIG. 2.

FIG. 6 is a perspective view of the ellipsoid vehicle mirror as shown inFIG. 1, the detail illustrating the proportional image views.

FIG. 7 is a perspective view illustrating the reflected image of a knownmirror illustrating the proportional image view.

FIG. 8-11 illustrate a perspective view, a front elevational view, a topelevational view and a side elevational view, respectively, of apreferred embodiment of a mirror assembly in accordance with the presentinvention.

FIG. 12 is an exploded perspective view of the mirror assembly depictedin FIGS. 8-11.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring now to FIG. 1, which is an illustration of an ellipsoidvehicle mirror assembly 10 in accordance with the present inventionmounted on a vehicle 12. Although the ellipsoid vehicle mirror assembly10 is illustrated mounted on a school bus, it should be understood thatthe present invention may be utilized in combination with a wide varietyof vehicles for a wide variety of applications. The ellipsoid vehiclemirror assembly 10 is well suited for vehicles such as trucks and vans.Similarly, although the ellipsoid vehicle mirror assembly 10 may bemounted in a variety of locations on the vehicle 12, one preferredembodiment contemplates mounting the ellipsoid vehicle mirror assembly10 on one or both of the front corners 14 of the vehicle 12. Mountingbrackets 16 are used to attach the ellipsoid vehicle mirror assembly 10to the vehicle surface 18.

When the ellipsoid vehicle mirror assembly 10 is mounted on the frontcorner 14 of the vehicle 12, it can provide the driver 20 with a fieldof view that encompasses both front-of-vehicle objects 22 andside-of-vehicle objects 24. The present invention provides advantages tothe driver's 20 field of view by improving the reflected view of thefront-of-vehicle objects 22 and the side-of-vehicle objects 24. This isaccomplished through the unique geometric configuration of the ellipsoidvehicle mirror assembly 1O. The ellipsoid vehicle mirror assembly 10 iscomprised of a base 26 (see FIG. 2). The base 26 in turn includes afirst base portion 28 and a second base portion 30. In the particularembodiment illustrated, the first base portion 28 and the second baseportion 30 are perpendicular to one another. It should be understood,however, that in alternate embodiments the base portions 28,30 may beformed parallel (see FIG. 3) or at any of a variety of angles relativeto each other.

The first base portion 28 is defined by a first base longitudinal line32 and a first base periphery 34. The first base periphery 34 is definedby a first base radius of curvature 36. The second base portion 30 isdefined by the first base longitudinal line 32 and a second baseperiphery 38 having a second base radius of curvature 40. It should beunderstood that when the base portions 28,30 are parallel, the firstbase longitudinal line 32 will not represent a visible dividing point. Adome lens 42 conforms to the base 26 and includes a varying dome lensradius of curvature 44. The dome lens 42 is a reflective convex surfacewith reflective mirror properties. A wide variety of configurations andmanufacturing methodologies are known for producing such a dome lens 42and are contemplated by the present invention.

The present mirror dome lens 42 may be manufactured from any suitable“silverized” plastic by any suitable mode such as injection moldingvacuum forming or the like. The materials of construction are preferablyselected such that upon formation there is no collapse at the centralportion of the lens to thus eliminate the potential of negativecurvatures and distortion thereat. Injection molding may be utilized inorder to mold the lens 42 to desired specifications. It should beunderstood, however, that a variety of manufacturing methodologies maybe utilized to implement the present invention.

The dome lens 42 is formed with a unique geometry to provide positivefield of view advantages in combination with improved image proportions.This is accomplished by forming the dome lens 42 as a major-axis tipportion 46 of an ellipsoid 48 (see FIG. 4). The major-axis tip portion46 comprises a portion of an ellipsoid 48 formed by dividing theellipsoid 48 generally across the major axis 50. The major-axis portion46 of the ellipsoid 48 preferably includes an ellipsoid tip point 52 asdefined where the major axis 50 intersects the ellipsoid perimeter 54.Although a wide variety of ellipsoids 48 are contemplated by the presentinvention, one embodiment contemplates the use of an ellipsoid 48 withan approximately 82 inch major axis 50 and a 29 inch minor axis 56. Inthis arrangement, the minor axis 56 is contemplated to be less than halfof the major axis 50. The dome depth 58, in this example, isapproximately 4.3 inches. It should be understood that these dimensionsand proportions are illustrative and are not meant as limitations to thepresent invention except as specifically claimed.

Although the ellipsoid 48 may be dimensioned and divided in a variety offashions, one embodiment contemplates that the first base portion 28divides the ellipsoid 48 perpendicular to the major axis 50. In thisembodiment the first base radius of curvature 36 is constant. When thesecond base portion 30 is perpendicular to the first base portion 28 (asin FIG. 2) the second base portion is then coincident with the majoraxis 50 and the ellipsoid tip point 52 is positioned on the second baseperiphery 38 at a position perpendicular to the first base longitudinalmidpoint 60. In this embodiment, the ellipsoid tip point 52 iscoincident with the second base periphery 38 and the second base radiusof curvature 40 is varying. In the embodiment (see FIG. 3) wherein thefirst and second base portions 28,30 are parallel, both first and secondbase radius of curvature 36,40 are constant and the ellipsoid tip point52 is positioned inbetween the first base periphery 34 and the secondbase periphery 38. It should be understood that the first and secondbaseline radius of curvatures 36, 40 in FIG. 3 are only constant whenthe ellipsoid 48 is divided perpendicular to the major axis 50. By usinga non-perpendicular intersection 59 (see FIG. 4), the first and secondbaseline radius of curvatures 36, 40 in FIG. 3 would both vary.

In still another contemplated embodiment (see FIG. 5), the ellipsoid tippoint 52 is still between the first base periphery and the second baseperiphery, however, both the first base radius of curvature and thesecond base radius of curvature are varying, In such a case, it isconceived that the angle between the first and second baseline portionsneed not be perpendicular but may encompass a variety of angles. Inaddition, square cut bisected base and square of sliver formations arealso contemplated.

The resultant described geometry results in a varying dome lens radiusof curvature 44′. The varying radius of curvature 44′ results in a thedome lens 42′ having a center surface portion 64 (see FIGS. 5 and 6), acenter surface radius of curvature 66 and a peripheral surface portion68 having a peripheral radius of curvature 70. The center surface radiusof curvature 66 corresponds to a position on the dome lens 42′ alignedwith the first base longitudinal midpoint 60′ in a directionperpendicular to the first base longitudinal line 32′. The peripheralsurface portion 68 corresponds to the first base periphery 34. Theperipheral surface radius of curvature 70 is greater than the centersurface radius of curvature 66. This in turn, as shown in FIG. 6,generates a first proportion image view 72 coincident with the centersurface portion 64 and a second proportion image view 74 coincident withthe peripheral surface portion 68.

The smaller radius of curvature of the center surface portion 64therefore results in a view generating smaller image proportions thanthe peripheral surface portion 68. In this manner, when the mirrorassembly 10 is positioned in the front corner 14 of the vehicle 12, itis preferably positioned such that the vehicle reflection 76 isreflected in the first proportion image view 72. The second proportionimage view 74 preferably reflects both the front-of-vehicle objects 22and the side-of-vehicle objects 24. Thus the vehicle 12 itself takes upa smaller portion of the mirror assembly 10 while the front-of-vehicleobjects 22 and the side-of-vehicle objects 24 are reflected withimproved proportions.

This benefits and advantages of the present invention are shown by acomparison of FIG. 6 with FIG. 7. FIG. 7 shows a corresponding reflectedimage view of a prior art mirror. The vehicle reflection 86 in FIG. 7 isapproximately 25% larger than the vehicle reflection 76 of FIG. 6. Inaddition, the reflected image of post 24B in the prior art mirror (FIG.7) is significantly smaller (approximately 50% in width) than thereflected image of corresponding post 24A in the present inventivemirror (FIG. 6). Posts 22A adjacent the edge of the field of view of thereflected image with the present invention (FIG. 6) are also larger,better defined and easier to see than corresponding post members 22B inthe reflected image of the prior art mirror (FIG. 7).

When the perpendicular base embodiment as shown in FIG. 2 is utilizedwith a constant first base radius of curvature 36, it is preferable thatthe second base portion 30 is approximately parallel with the vehiclehood plane 78 (see FIG. 1) and the ellipsoid tip point 46 is positionedcloser to the vehicle 12 than the first base periphery 38. In thismanner, the vehicle 12 is properly relegated to the first proportionimage view 72 as shown in FIG. 6, while the second proportion image view74 covers the entire range of front-of-vehicle to side-of vehicle.

One preferred mirror lens configuration 90 is shown in FIG. 4A. Thecurvature 92 along the mid-point of the front surface of the mirror lens90 follows the curvature of one end 94 of an ellipsoid 54′. Thecurvature along the surface of the mirror lens transverse to curvature92 also follows along the curvature of the ellipsoid. The upper andlower surfaces 96 and 98, respectively, of the mirror lens 90 arecut-off as truncated in the manner shown in FIG. 4A.

A schematic depiction of a preferred mirror assembly 100 in accordancewith the present invention is shown in FIGS. 8-12. The assembly 100includes a mirror lens 110, a housing or base member 120, and anelastomeric gasket member 130. As shown in the exploded view in FIG. 12,the base member 120 has an outer rim or recess 122 adapted to hold theouter edges of the mirror lens 110. The gasket member 130 is positionedover the mated lens and base member after they are assembled together.In order to hold the three components tightly together, it is preferableto securely affix the lens to the base member with glue or the like. Itis also possible to glue or otherwise securely attach the gasket memberover the interface between the base member and lens. The gasket memberassists in sealing that interface and prevents moisture, dust, etc. fromentering into the center of the mirror assembly,

FIG. 10 also illustrates one of the aspects of the invention. Asindicated by the arrows schematically representing the radii of thecurvature 112 along the major axis 114 of the surface of the lens 110,the radius R1, at the mid-point 116 is smaller or shorter in length thanthe radii R2 at the areas of the surface along the major axis 114 awayfrom the mid-point and closer to or adjacent the outer periphery oredges of the lens.

While particular embodiments of the invention have been shown anddescribed, numerous variations and alternative embodiments will occur tothose skilled in the arm. Accordingly, it is intended that the inventionbe limited only in terms of the appended claims.

1. A mirror assembly comprising: a housing member, a mirror lens member,and a connecting member connecting said housing and mirror lens memberstogether; said mirror lens member having a varying radius of curvaturewith a center surface portion having a first radius of curvature and aperipheral surface portion having a second radius of curvature, saidsecond radius of curvature being greater than said first radius ofcurvature, wherein said center surface portion forms a first proportionimage view and said peripheral surface portion forms a second proportionimage view, said first proportion image view generating smaller imageproportions than said second proportion image view.
 2. The mirrorassembly as described in claim 1, wherein said mirror lens membercomprises a major tip portion of an ellipsoid.
 3. The mirror assembly asdescribed in claim 1 wherein said connecting member is a gasket member.4. A multi-piece mirror assembly comprising: a housing member; and amirror lens member connected to said housing member; said mirror lensmember comprising a major axis tip portion of an ellipsoid, said majortip portion formed by dividing said ellipsoid across a major axis, saidmirror lens member generating a first proportion image view and a secondproportion image view, said first proportion image view generatingsmaller image proportions from said second proportion image view, saidfirst proportion image view positioned at an ellipsoid tip point.
 5. Themulti-piece mirror assembly as described in claim 4 further comprising aconnecting member positioned over the interface between said housingmember and mirror lens member after they are positioned together.
 6. Themulti-piece mirror assembly as described in claim 4 wherein saidellipsoid is divided perpendicular to said major axis and then furtherdivided parallel to said major axis to form said major axis tip portion.